21320109 has 12 divisors (see below), whose sum is σ = 32416800. Its totient is φ = 13465224.

The previous prime is 21320107. The next prime is 21320183. The reversal of 21320109 is 90102312.

It is a happy number.

It is not a de Polignac number, because 21320109 - 2¹ = 21320107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21320091 and 21320100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62169 + ... + 62510.

It is an arithmetic number, because the mean of its divisors is an integer number (2701400).

Almost surely, 2^21320109 is an apocalyptic number.

It is an amenable number.

21320109 is a deficient number, since it is larger than the sum of its proper divisors (11096691).

21320109 is a wasteful number, since it uses less digits than its factorization.

21320109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124704 (or 124701 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 21320109 is about 4617.3703555162. The cubic root of 21320109 is about 277.2871901408.

The spelling of 21320109 in words is "twenty-one million, three hundred twenty thousand, one hundred nine".